Greetings
For the High Elves of this world I can think of 2 concepts with a central idea.
Concept 1) In the capital and major cities, the architecture could be marble, green glass domes and gold decorations. In smaller settlements and those closest to the border, structures could be built inside large trees or in the tops of them.
Concept 2) In the capital and main settlements we could see structures like those of the Lothlorien elves, while in smaller settlements and periphery we could see something like the halls of Thrandruil in the Black Forest.
In any case, all this would be inside the forest. If they have settlements in the mountains or in open spaces or closed the sea, the main architecture would be the one exposed for the capitals of concept 1.
See you.